CN1148197C - Ginkgo biloba flavonoid extract free of terpenes and/or having a high content of flavonoid isoglycosides - Google Patents

Abstract

The present invention relates to flavonoid extracts of ginkgo biloba leaves, in particular to extracts which are terpene-free and/or have a high content of flavonoid isoglycosides. Also relates to flavouring compounds containing such an extract and to the use of the extract as a flavouring ingredient. Finally, it relates to a process for obtaining a ginkgo biloba leaf flavonoid extract substantially free of terpenes.

Description

Ginkgo flavonoid extract free of terpenes and/or high in flavonoid isosides

The present invention relates to flavonoid extracts of Ginkgo biloba, more particularly to extracts which are substantially free of terpenes or have a high content of flavonoid isosides, or are free of terpenes and have a high content of flavonoid isosides Glycosides. The extract can be effectively used as a flavoring agent. The invention also relates to flavoring compositions containing such extracts and the use of such extracts as flavoring ingredients.

The medicinal and cosmetic applications of Ginkgo biloba extracts are well known. The extract EGb-761 is probably the most familiar in the medical field (The extract of ginkgobiloba [EGb-761], La Presse Médicale, 1986, Vol.31, Special Number, Masson Publishing Co.). The extract mainly contains two types of substances: flavonoids and terpenes. The new extracts have shown, in a surprising manner, to improve the sensory properties of certain foods such as beverages, dairy products and confectionery.

Therefore, one aspect of the present invention is to make the extract of interest without any or only a small amount of terpenes (Ginkgolide and Bilobalide), which are highly therapeutically active. In addition, it has been found interesting to obtain extracts rich in flavonoids: they are essentially monosodium glutamate of kaempferol, quercetine and lsorhamnetine with glucose and rhamnose. , two and three glycosides.

The object of the present invention is also a terpene-free flavonoid extract of Ginkgo biloba leaves. This indicates that the extract includes flavonoid isosides and little or no terpenes. If the extract contains terpenes, the maximum terpene content is 1%, preferably maximum 0.5%.

The object of the present invention is also a flavonoid extract having a high content of flavonoid isosides. This means that the extract contains 28-35% flavonoid isosides, and preferably 28-32%. This extract is preferably obtained from the pruned leaves of young Ginkgo biloba.

The object of the present invention is also a flavonoid extract free of terpenes and having a high content of flavonoid isosides. This means that the extract is terpene-free and contains 28-35% flavonoid isosides, preferably 28-32%.

More specifically, the present invention is aimed at flavonoid extracts containing up to 1% terpenes and 28-35% flavonoid isosides. The extract preferably contains at most 0.5% terpenes and 28-32% flavonoid isosides.

Flavonoid extracts with a high content of flavonoid isosides can be obtained by extraction with acetone-water mixtures under partial vacuum. After removing lipids, using various solvents, and removing unnecessary substances by precipitation, the extract solution was concentrated, and the extract was vacuum-dried.

The subject of the invention is also a process for the preparation of a terpene-free extract as defined above. The method comprises several extraction steps of extracting ginkgo leaves with a solvent, characterized in that one of the extraction steps is a deterpening step, and the solvent used is a compound of formula RC(O)OR ¹ itself or a mixture containing at least 5 carbons Atoms of saturated aliphatic hydrocarbons, where R and ^R1 each represent a lower alkyl group. This extraction step can be performed at any stage of the process. The solvent used in the deterpenation step preferably contains 0 to 20% saturated aliphatic compound.

Extraction steps other than the deterpenation step are known in the literature, especially in Patents EP431535, EP431536, EP360556 and EP324197. These patents are incorporated herein by reference.

In the foregoing definition, the term "lower alkyl" preferably means a linear or branched alkyl group containing 1 to 6 carbon atoms, especially an alkyl group containing 1 to 4 carbon atoms such as methyl, ethyl, Propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl. Solvents of the formula RC(O)OR ¹ in which the R and R ¹ groups represent methyl, ethyl or propyl, especially ethyl acetate are preferably used.

The saturated aliphatic hydrocarbon can be selected from hexane, heptane or octane, heptane being preferably used.

The object of the present invention is also a process for the preparation of an extract rich in flavonoid isosides as defined above. The method comprises several extraction steps of Ginkgo biloba leaves with a solvent, characterized in that one of the extraction steps is a step of enrichment of flavonoid isosides, and the solvent used is a minimum amount of alcohol alone or mixed with alcohol, preferably acetone ketone. This extraction step can be performed at any stage of the process. The alcohol used is preferably a lower alcohol such as methanol, ethanol, propanol or butanol, and preferably butanol. The solvent can be used in an amount of 3 to 12 parts, and is preferably a lower part in this range.

An example is described in the experimental part below, the order of the extraction steps with ethyl acetate/heptane mixture and acetone-butanol mixture can be reversed.

The extracts according to the invention improved both the olfactory and gustatory properties of the tested products. In view of its organoleptic properties, the extract can be used in the preparation of various aromatic compositions. It can be used alone or in combination with other commonly used flavoring ingredients. Therefore, this flavonoid extract is expected to be used in food. As food products, dairy products such as yoghurt, soft drinks or nutritional drinks, more precisely non-alcoholic refreshing drinks such as orange juice drinks or tonics based on quinine, but also products with added sugar such as chewing gum, may be mentioned.

The amount used for the flavoring composition or flavoring can vary within a wide range of values: it should be understood that the value depends not only on the product to be flavored or flavoring composition, but also on the properties of the other ingredients of the flavoring composition. The nature and amount also depend on the desired effect.

The used flavonoid extract of the present invention has a concentration range of 0.001-0.1 wt%, preferably 0.001-0.05%, relative to the total weight of the seasoning product. As for dairy products, the concentration of the flavonoid extract may range from 0.005 to 0.045%. As for products such as chewing gum, the concentration range of flavonoid extract can be 0.01-0.04%. As for foods such as soft drinks or nutritional drinks, the concentration of the flavonoid extract may range from 0.002 to 0.02%.

The following examples are given to illustrate the invention but are not to be construed as limiting it in any way.

the scope of the invention.

Embodiment 1 : the method for obtaining flavonoid extract

Extract ginkgo leaves with 6-12 parts (preferably 8 parts) of water containing 60% acetone at 50-60° C., then concentrate the solution to reduce the percentage of acetone to less than 3%. The solution was cooled and freed of lipids by decantation. The aqueous solution was extracted with 2-5 parts of ethyl acetate containing 0-20% heptane. The resulting solution was extracted with a minimal amount of acetone-butanol mixture (0-15% acetone) in the presence of ammonium sulfate. The organic phase was concentrated; after addition of ethanol, the solution was concentrated again. After diluting with ethanol, the solution was cooled, and the insoluble precipitate was filtered off. The resulting solution was concentrated, dried and finally pulverized to recover the flavonoid extract in the form of a uniform powder.

Embodiment 2 : sensory analysis

The sensory analysis performed on the flavonoid extract obtained in Example 1 was to analyze some food products (dairy products, soft drinks and chewing gum) with and without flavonoid extract.

Sixty tasters participated in this analysis. For each sensory item (acidity, bitterness, sweetness, salinity), each taster indicated a level of intensity corresponding to the evaluation of the tested product on an increasing scale from 0 to 5.

Example 2a: Dairy products traditional kefir solids Light Yogurt Solids Q(mg/bottle) 0 10 25 0 10 25 Acidity 4 3 2.5 Bitterness 2.5 2.5 2.5 Sweetness 1 2.5 2 Salinity 1 1.5 2 3 2.5 32 2.5 1.5 2.5 2 1.53 2 2

Q = amount of extract traditional kefir blend light mixed yogurt Q(mg/bottle) 0 10 15 0 10 15 Acidity 4 3 2.5 Bitterness 2 2 2.5 Sweetness 2 2.5 2 Salinity 2 2.5 2 2 2.5 22 2.5 24 3 22 2.5 2 sweetened natural drink kefir Q(mg/bottle) 0 50 100 Acidity 3 3.5 3 Bitterness 1 1.5 1.5 Sweetness 3.5 3 3 Salinity 1 1 1

The astringent taste of the extract itself and the basic taste of dairy products can be well balanced by reducing the acidity of traditional products. The extract appears to have a good complement of dairy and fruity properties.

Example 2b: refreshing drink Tonic based tonic drink orange juice drink Q(mg/l) 0 50 100 0 50 100 Acidity 2 2.5 3 Bitterness 3 2.5 3 Sweetness 2.5 2.5 3.5 Salinity 0.5 0.5 0.5 2.5 3 3.52 3.5 43.5 2.5 42 1 1

The astringency of the extract can harmonize with the astringency of beverages, more specifically with quinine-based beverages and/or bitter bark such as Indian Tonic ^(R) .

Example 2c: Chewing gum Peppermint Gum Chlorophyll Gum Other Peppermint Gum U(mg/unit) 0 3 6 0 6 12 0 3 6 Freshness Spicy Sweetness Grassy 4 2 14 3 13 3.5 40 2 4 2 3 12 2 12 3 42 3 4 2 3 12 2 13 4 41 2 4

U: unit

Example 3: Illustrative Test

The test was carried out with several yoghurts. Sixty tasters, consumers of natural yoghurt, participated in the test. The method used was a comparative test of sensory properties. The questionnaire contains 9-10 descriptors according to "Solid" or "Mixed" test species. Each taster indicates the degree of perception on a 10 cm non-integral texture scale for each item, and this test is performed on all products in turn. The results obtained are as follows:

Example 3a: Product tested: Yogurt solids with 0% fat matter, with or without 0.04% flavonoid extract from Example 1

  Varieties with extracts Varieties without extracts

Description Item Mean Standard Deviation Mean Standard Deviation t S

Firmness 6.68 1.35 6.58 1.52 0.81

Overall Fragrance 5.00 1.72 4.77 1.72 1.42

in the mouth

6.54 2.03 6.34 1.79 1.18

smoothness

Density 4.90 1.54 4.73 1.73 0.97

in the mouth

2.31 1.98 2.04 1.91 1.95

greasy feeling

Fruity 2.65 2.10 0.70 1.02 8.36 1%

Fermented flavor 2.99 2.33 3.22 2.13 1.28

Sour 2.74 2.07 2.67 1.98 0.33

Bitterness 2.07 1.82 1.42 1.31 3.95 1%

t = Student's T-test for paired series; S = degree of significance

The varieties containing flavonoid extracts were distinguished from the varieties without flavonoid extracts in a rather marked manner by having a more pronounced fruity and stronger bitter taste.

Example 3b: Product tested: Yoghurt solids with and without 0.04% flavonoid extract from Example 1

Products with extracts Products without extracts

Description Item Mean Standard Deviation Mean Standard Deviation t S

Firmness 7.65 1.60 7.38 1.36 2.06 5%

Overall Fragrance 4.85 1.85 4.81 1.92 0.27

in the mouth

7.01 1.99 6.87 2.12 0.92

smoothness

Density 6.26 2.05 5.46 1.91 4.92 1%

in the mouth

4.17 2.08 3.54 1.95 3.59 1%

greasy feeling

Fruity 2.25 1.99 0.84 1.19 6.04 1%

Fermented flavor 2.62 2.06 2.66 2.19 0.24

Sour 2.62 1.72 2.61 1.59 0.05

Bitterness 1.69 1.55 1.53 1.49 0.88

t = Student's T-test for paired series; S = degree of significance

Products containing flavonoid extracts differed from other products by having a thicker consistency in the mouth, a more unctuous and more pronounced fruity taste in a highly significant manner and a higher firmness on the spoon Varieties containing flavonoid extracts.

Example 3c: Product tested: Fat mixed yogurt with and without 0.04% flavonoid extract from Example 1

Products with extracts Products without extracts

Description Item Mean Standard Deviation Mean Standard Deviation t S

5.29 1.71 5.22 1.71 0.56 on spoon

consistency

on the spoon

3.52 1.91 3.50 1.80 0.20

Sticky

Overall Fragrance 4.36 1.69 4.32 1.68 0.27

in the mouth

8.23 1.48 8.17 1.63 0.66

smoothness

Density 3.99 1.96 4.06 2.04 0.45

in the mouth

                                                                    

Creamy feeling

Fruity 2.60 1.92 1.09 1.31 5.97 1%

Fermented flavor 3.19 2.20 2.94 2.27 1.11

Sour 3.10 2.00 2.47 1.71 2.63 5%

Bitterness 2.00 1.78 1.53 1.57 2.35 5%

t = Student's T-test for paired series; S = degree of significance

Products containing flavonoid extracts are distinguished from products without flavonoid extracts by having a more pronounced fruity taste in a rather marked manner and by being more sour and more bitter in a marked way.

Claims (16)

1. seasoning composition, it contains the flavonoid extract of flavonoid heteroside that derives from Folium Ginkgo, contain maximum 1% terpenes and 28-35 weight % separately as flavoring ingredients or also contain other flavoring agent, extract described flavonoid extract from Folium Ginkgo and comprise, be characterised in that with the several steps of solvent extraction Folium Ginkgo:

I) one of extraction step is to take off the terpenes step, and solvent for use is formula RC (O) OR ¹Chemical compound itself or its mix with the radical of saturated aliphatic hydrocarbon phase that comprises at least 5 carbon atoms, R and R1 represent low alkyl group separately in the formula, and

Ii) one of extraction step is the step of enrichment flavonoid heteroside, and solvent for use is to be mixed with ketone in the independent alcohol of minimum flow or the alcohol.

2. according to the seasoning composition of claim 1, wherein said extract contains and is less than 0.5% terpenes.

3. according to the seasoning composition of claim 1, wherein said extract contains 28～32% flavonoid heteroside.

4. according to the seasoning composition of claim 1, wherein said ketone is acetone.

5. one kind with each the goods of compositions seasoning of claim 1-4.

6. according to the goods of claim 5, it is a kind of milk product.

7. according to the goods of claim 6, wherein said milk product is a clabber.

8. according to the goods of claim 5, it is a kind of beverage.

9. goods according to Claim 8, wherein said beverage is the soft drink of non-ethanol.

10. according to the goods of claim 5, it is a kind of goods of sugaring.

11. according to the goods of claim 10, it is chewing gum or confection.

12. each compositions of claim 1-4 is in Application in Food.

13. the flavonoid extract of flavonoid heteroside that derives from Folium Ginkgo, contains maximum 1% terpenes and 28-35 weight % extracts described flavonoid extract from Folium Ginkgo and comprises with the several steps of solvent extraction Folium Ginkgo as the purposes of flavoring ingredients, is characterised in that:

I) one of extraction step is to take off the terpenes step, and solvent for use is formula RC (O) OR ¹Chemical compound itself or its mix R and R in the formula at least with the radical of saturated aliphatic hydrocarbon phase that comprises 5 carbon atoms ¹Represent low alkyl group separately, and

Ii) one of extraction step is the step of enrichment flavonoid heteroside, and solvent for use is to be mixed with ketone in the independent alcohol of minimum flow or the alcohol.

14. according to the purposes of claim 13, wherein said extract contains and is less than 0.5% terpenes.

15. according to the purposes of claim 13, wherein said extract contains the flavonoid heteroside of 28-32%.

16. according to the purposes of claim 13, wherein said ketone is acetone.